You can get the basic skeleton content from some of the competitor websites. Then review that carefully for what makes sense for your business, and for your product. For example, if you offer login via LinkedIn or Twitter and your competitors do not offer that, add a specific section on 'using external party services for login and profile details'.

Nothing legal so far.

Next, get your attorney involved for a review, for consistency and clarity of message. Give the competitors' websites to your attorney too, to ensure that everything you 'pick' makes sense. Second opinion always helps. It also ensures that legal jurisdiction for various conditions is correctly mentioned.